Magnetostriction-polarization coupling in multiferroic Mn<sub>2</sub>MnWO<sub>6</sub>.

Li, Man-Rong; McCabe, Emma E; Stephens, Peter W; Croft, Mark; Collins, Liam; Kalinin, Sergei V; Deng, Zheng; Retuerto, Maria et al. · Nat Commun · 2017

basic_science · Level V

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Abstract

Double corundum-related polar magnets are promising materials for multiferroic and magnetoelectric applications in spintronics. However, their design and synthesis is a challenge, and magnetoelectric coupling has only been observed in Ni<sub>3</sub>TeO<sub>6</sub> among the known double corundum compounds to date. Here we address the high-pressure synthesis of a new polar and antiferromagnetic corundum derivative Mn<sub>2</sub>MnWO<sub>6</sub>, which adopts the Ni<sub>3</sub>TeO<sub>6</sub>-type structure with low temperature first-order field-induced metamagnetic phase transitions (T <sub>N</sub> = 58 K) and high spontaneous polarization (~ 63.3 μC·cm<sup>-2</sup>). The magnetostriction-polarization coupling in Mn<sub>2</sub>MnWO<sub>6</sub> is evidenced by second harmonic generation effect, and corroborated by magnetic-field-dependent pyroresponse behavior, which together with the magnetic-field-dependent polarization and dielectric measurements, qualitatively indicate magnetoelectric coupling. Piezoresponse force microscopy imaging and spectroscopy studies on Mn<sub>2</sub>MnWO<sub>6</sub> show switchable polarization, which motivates further exploration on magnetoelectric effect in single crystal/thin film specimens.